Ornamental rustless iron product and art of making the same



Patented Oct.-

1,977,270 ORNAMENTAL RUSTLESS IRON PRODUCT 1 a ART oF MAKING THE SAMEAlexandenIaFeild, Baltimore, Md., assignor to Alloy ResearchCorporation, Baltimore, Md.

no Drawing.

11 Claims.

This invention relates to an ornamental rustless iron or steel productand to an art of producing the same.

Among the, objects of my invention are the 5 production in a simple,efiicient and thoroughly practical manner of a rustless iron product'ormanufacture which is decorative, ornamental and attractive to the eye; aproduct that is strong, tough, durable as well as corrosion-resistant orrustless; one that is adapted to exterior ornamental or decorative worksuch as balconies, rails, fences and gates, and especially to interiorapplications such as rails, trim, grilles or inside balconies as well asobjects of art such as urns, bowls or vases, or ornamental hardware suchas locks, hinges, hasps, and the like; and which retains its decorativeor ornamental characteristics under the many varying conditions ofactual practical use.

The invention, accordingly, consists in the features of construction,combination of elements and arrangement of parts, and in the severalsteps and the relation of each of the same to one or more of the othersas described herein and 25 the scope of the application of which isindicated in the following claims.

As conducive to a clearer understanding of certain features of myinvention it may at this point be noted that in heretofore known and/orused methods of producing corrosion-resistant decorativeornamentalironwork, for either interior or exterior applications, either a rough,scaly surface is allowed to remain on the rustless iron product, whenthe appearance is of no consequence, or the scale is removed bysand-blasting,

grinding and/or pickling to give a dull smoothfinish, or the surface ofthe product may then be buffed or polished whereby a finish ranging froma satin to a bright mirror-like surface is achieved as desired.

Also, in -heretofore known and/or used methods of producing ornamentalironwork, the product may be given a final finish of a desiredcolor andsurface quality by a suitable paint, cement or other coating compound.Such coatings, in addition to being initially expensive, are ofnecessity impermanent, requiring constant attention and repair withfrequent renewal at considerable inconvenience and expense.

One of the objects of my invention is the production of a rustless irondecorative or ornamental product in a simple, enexpensive, eflicient andthoroughly reliable manner, having a surface, 55 permanent andcorrosion-resistant, which is Application November 2, 1932, Serial No.640,902

pleasing and attractive to the eye both as to color and as to qualityand finish.

Referring now more particularly 'to the manner of producing a decorativeor ornamental product, illustratively a piece of ornamental hardware, inaccordance with my invention, a piece of sheet, strip, plate or barstock of a rustless iron (a ferrous alloy containing from 12-25%chromium and about .15% carbon, either with or without additionalalloying elements such as nickel, 35 copper, tungsten and vanadium); isfirst cut, stamped and otherwise shaped to conform to a desired patternor design. The shaping may be carried out either with the stock hot orcold, depending upon the shape ofobject desired and the 7 amount ofworking necessary.

Thus, for example, a piece of rustless iron plate stock analyzing 17%chromium, .08% carbon, with small amounts of silicon and manganese andtraces of sulfur and phosphorus, is forged to form a fancy ornamentalhinge.

To relieve internal stresses incident to the forging, the product isconveniently annealed by heating it for about two hours at a temperatureof approximately 1525 F. and then allowing it to slowly air cool atnormal room temperature.

As a result of the working and annealing indicated above a scale isformed on the product. This scale is conveniently removed by picklingthe product in a bath comprising an aqueous solution of 20% nitric acidand a 1% solution of hydrofluoric acid. After the scale is fullyremoved, traces of the picking solution are removed by washing theproduct in running water. Conveniently the product is dried in anysuitable manner before a further working of its surface is undertaken.

To give a wrought or reticulate appearance which is ornamental andpleasing to the eye', the article is hammered in any convenient fashion,as with the ball-peen of a machinist hammer, until the surface issuitably covered with a myriad of small indentations which may cover theentire surface exposed to view or any part of it as desired.

The article or product is then preferably dipped in a 10% nitric acidsolution to free its surface of any minute adhering particles of ironfrom the hammer or other tool with which its surface has just beenworked. This dip may be followed by washing and drying the product inany convenient fashion.

An attractive finish is given the article by heating it until thesurface becomes tinted to, for example, the rich color of old gold.Rustless iron, as in the case of ordinary low carbon iron, progressivelypasses through the various colors light straw, dark straw,yellowish-brown, redbrown, deep purple, violet, blue and green as theproduct is gradually heated. In the case of rustless iron, however, theband of colors ranging from light straw to yellowish brown is broadenedout, these colors persisting longer during the heating of the product.By a reasonably careful control of the length of time that the productis exposed to the source of heat as compared with the temperature of theheating agent, a deep rich color of old gold may be given the surfaceing the article during the heating period and the the many desirablecharacteristics of rustless,

length of time that the article is subjected to the heating action ofthe heating agent.

Thus, for a fiat, relatively thin article, such as an ornamental hinge,a desired old gold finish is achieved by subjecting the hinge to theheat of a gas-fired furnace operating at a temperature of about 1750 F.for a period of some fifty seconds.

Another ornamental and attractive finish may be given the article byfurther treatment of grinding or polishing off the outermost portions ofthe reticulations as by means of an emery belt or other abrading machineto expose the silver white metal beneath. The contrast between the spotsof dull gold color and those of the bright silvery appearance produces apleasing and highly artistic efiect.

Before using the article, finished either with or without the furthertreatment described above,

, it is preferably given a passivating treatment by dipping in anaqueous solution of 10% nitric acid.

. The surface of the article is then washed clean under running waterand suitably dried.

A' product or article having the many beneficial characteristics ofrustless iron, such as its corrosion-resistant, hardness and strength,coupled with the durable and attractive heat-tinted finish is thusproduced without in any way affecting the rustless orcorrosion-resistant characteristics of the material.

For example,.an article prepared in accordance with my processwithstands a standard loo-hour salt-spray test (4% sea-salt solution)without showing any appreciable corrosion or discoloration.

Thus it will be seen that there has been-provided in this invention anart and product in which the various objects hereinbefore noted,

together with many thoroughly practical advantages are successfullyachieved. It will be seen that the product is strong, durable andcorrosionresistant, and that it is given a permanent and attractivefinish in a simple, direct and thoroughly practical manner all withoutsacrifice to iron.

While in treating the shaped article, as hereinbefore described, awrought or reticulated'surface was given it prior to the heat tintingthereof, certain beneficial results, such as a smoother but somewhatduller finish to the depressed areas, may be achieved by heat-tintingthe article first and then giving its surface the wrought appearance.Or, if desirable, the article may be used with the smooth old goldcolored satin finish without the wrought or reticulated eifect.

Similarly, certain economies in practice, such as saving in time andexpenditure of effort, may be achieved by working the article at theheattinting temperature.

As many possible embodiments may. be made of my invention and as manychanges or alterations may be made in the embodiment hereinbefore setforth, itis to be understood that all matter described herein isyto beinterpreted as illustrative and not in a limiting sense.

1. Ina manufacture of the class described, a rustless iron producthaving a corrosion-resistant heat-tinted surface.

2. In a manufacture of'the class described, a rustless iron producthaving an indented or reticulated corrosion-resistant heat-tintedsurface.

3. In a manufacture of the class described, a rustless iron producthaving an indented or reticulated corrosion-resistant heat-tintedsurface, the outermost portions of which are removed to expose the basemetal.

4. In a manufacture of the class described, a rustless iron producthaving a corrosion-resistant surface heat-tinted to about the color ofold gold.

5. In a manufacture of the class described, a rustless iron producthaving a reticulated corrosion-resistant surface heat-tinted to about astraw color.

6. In a manufacture of the class described, a rustless iron producthaving a reticulated corrosion-resistant surface, the reticulatedportions of which are heat-tinted to a straw color and the remainingportions of which are of the bright base metal.

'7. In a manufacture of the class described, the art which comprises,heat-tinting a rustless iron product to a straw color to give acorrosion-resistant tinted surface.

8. In a manufacture of the class described, the art which comprises,producing a wrought product of rustless iron, and then heat-tinting thesurface of said product to an old gold color without detracting from therustless or corrosionresistant character of the product.

9. In a manufacture of the class described, the art which comprises,heat-tinting a rustless iron product to give a corrosion-resistanttinted surproducing a wrought effect without detracting .from therustless character of the surface.

10. In a manufacture of the class described, the art which comprises,deforming a rustless iron product to give a surface having a wroughtappearance, heating the product to produce a tinted surface, and thenremoving a portion of the heattinted surface to expose the underlyingrustless metal of the product.

11. In a manufacture of the class described, the art which comprises,deforming a rustless iron product at a temperature sufiiciently high soas to cause a heat-tinting of the surface of the product during thedeformation thereof whereby a desired corrosion-resistant tinted surfaceof a1 wrought metal product is achieved.

ALEXANDER L. FEILD.

